Non-invasive Process Fluid Temperature Induction with Curved Sensor Capsule

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Non-invasive process fluid temperature estimation systems face errors due to variability in heat flow paths and air gaps between flat sensor ends and curved conduits, limiting their accuracy and applicability, especially in remote and high-temperature applications.

Innovation Solution

The system employs a pipe clamp with a heat flow sensor capsule that securely contacts the conduit surface, using a spring to ensure contact and includes temperature sensors with staggered bores and a machined tip for precise spacing, along with a compensation curve for conduit diameter to correct for air gap thermal resistance, improving accuracy by minimizing heat flow variability and air gap errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a flat sensor capsule is used to contact the conduit surface, then the device complexity is reduced and ease of manufacture is improved, but measurement precision deteriorates due to air gaps between the flat sensor end and curved conduit surface

Engineering Contradiction:
Improveease of manufactureVSAvoidmeasurement precision
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The sensor capsule end is formed with a curved surface that matches the curvature of the conduit surface, eliminating air gaps between the sensor and conduit. This curved geometry ensures consistent thermal contact across the interface, improving measurement precision while maintaining ease of manufacture through standardized curvatures for different conduit sizes.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Adaptability or versatility

If non-invasive external temperature measurement is used, then the device can be deployed at any location without requiring conduit apertures or ports, but measurement precision deteriorates due to variability in heat flow paths through the conduit wall

Engineering Contradiction:
ImproveadaptabilityVSAvoidmeasurement precision
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system replaces direct mechanical contact temperature measurement with a non-invasive external measurement approach. Temperature is measured from the outer surface of the conduit using a sensor capsule that contacts only the external surface, eliminating the need for conduit apertures, ports, or penetrations while maintaining adaptability for deployment at any location.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If a spring is added to ensure sensor contact with the conduit surface, then measurement precision is improved through consistent thermal contact, but device complexity increases

Engineering Contradiction:
Improvemeasurement precisionVSAvoiddevice complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The sensor capsule incorporates a compliant mounting mechanism with adjustable spring pressure that can be tuned to optimize thermal contact. The spring force parameter is adjusted to ensure consistent contact between the curved sensor surface and conduit surface, improving measurement precision while keeping the added complexity minimal through a single adjustable parameter.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach enhances the accuracy of process fluid temperature estimation by controlling heat flow variability and correcting for conduit geometry, enabling more reliable and precise temperature measurements across various conduit diameters and applications.

Implementation Method 1

measuring an external temperature of a process fluid conduit... employ a heat flow calculation... heat flow calculation with the process fluid conduit skin temperature information

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3857189B1Non-invasive process fluid temperature indication with reduced error
Publication Date: 2025.01.15 ROSEMOUNT INC
  • EP3857189B1 patent drawingFigure 1
  • EP3857189B1 patent drawingFigure 2
  • EP3857189B1 patent drawingFigure 3A~3B

AI summary

A process fluid temperature estimation system includes a mounting assembly, a sensor capsule, measurement circuitry, and a controller. The mounting assembly is configured to mount the process fluid temperature estimation system to an external surface of a process fluid conduit. The sensor capsule has an end that is configured to contact the external surface of the process fluid conduit to form an interface having a contact region and an air gap. The sensor capsule also has at least one temperature sensitive element disposed therein. The measurement circuitry is coupled to the sensor capsule and configured to detect an electrical characteristic of the at least one temperature sensitive element that varies with temperature and provide at least process fluid conduit skin temperature information. The controller is coupled to the measurement circuitry and is configured to obtain the process fluid conduit skin temperature information from the measurement circuitry and to obtain reference temperature information. The controller is configured to obtain a heat flow parameter related to the air gap of the interface and to employ a heat transfer calculation with the process fluid conduit skin temperature information, reference temperature information, and heat flow parameter to generate an estimated process fluid temperature output.